1. Field
The following description relates to a case for a secondary battery and a method of manufacturing the case.
2. Description of the Related Art
Unlike primary batteries that are not rechargeable, secondary batteries are rechargeable and widely used in electronic devices such as cellular phones, PDAs, and laptop computers. Particularly, lithium ion secondary batteries have operating voltage of 3.6 V which is three times higher than the operating voltage of nickel-cadmium or nickel-hydrogen batteries that are widely used as power sources of electronic equipment, and the use of lithium ion secondary batteries is rapidly increased owing to their high energy density per weight.
In addition, as compared with other secondary batteries, lithium ion secondary batteries have high output power, high capacity, and low weight, and thus they are also used in internal combustion engine vehicles, hybrid electric vehicles, or electric vehicles.
In addition, lithium-containing oxides are usually used as positive electrode active materials of lithium ion secondary batteries, and carbon is usually used as negative electrode active materials of lithium ion secondary batteries. Lithium ion secondary batteries are manufactured with various shapes such as cylindrical shapes, prismatic shapes, and pouch shapes. A lithium ion secondary battery includes an electrode assembly and a conductive case in which the electrode assembly is accommodated.